Even the tiny phytoplankton: Guana Tolomato Matanzas NERR tracks life both large and small

By on January 26, 2018

GTM SWMP Manager Shannon Dunnigan (top) and CTP Coordinator Kaitlyn Dietz working on the weather station. (Credit: GTM Research Reserve)

While Guana Tolomato Matanzas National Estuarine Research Reserve (GTM NERR) environmental monitoring shares some features with other NERRs across the U.S., it also has some features that make it unique. Not every NERR monitors mangroves. GTM NERR also monitors such diverse species as oysters, butterflies and yes, even tiny plankton.

Pamela Marcum, Biological Scientist II at GTM NERR, explains both standard and distinctive monitoring at the Reserve. “The GTM Research Reserve participates in the NERRS System-Wide Monitoring Program (SWMP) that conducts long-term monitoring of water quality, meteorology and emergent vegetation,” she says.  GTM NERR water quality monitoring is done using YSI EXO2 water loggers and YSI PRO 2030 handheld water loggers that collect salinity, dissolved oxygen, temperature, conductivity, pH, turbidity and water depth data. GTM also uses OnSet HOBO water loggers that measure water depth, salinity and temperature. A Campbell Scientific CR-1000 meteorological station is used to measure air temperature, wind speed and direction, barometric pressure, humidity and precipitation.

Like other NERRs, GTM monitors vegetation. GTM vegetation monitoring is primarily conducted visually and with physical measurements. but a YSI hand-held is also used to measure temperature and salinity of porewater samples. Real Time Kinematic (RTK) surveying equipment is used to collect elevation data on GTM instruments. Monitoring also includes surveying land elevation using the NERRs’ shared Spectra Precision EPOCH 50 Real Time Kinematic GPS.

Trimble Geo7X and Garmin GPSMAP 76CSx handheld GPS units are also used to record data points in the field. Garmin echoMAP 74sv GPS with scanning sonar is used to record positional data on the water and conduct bathymetric scans.

In addition to SWMP, GTM NERR also conducts long-term monitoring of oyster populations, phytoplankton and mangroves within the GTM estuary.

“The oyster monitoring program is still in its developmental stages, but it involves taking random samples of oysters to assess population density and size classes, as well as evaluating overall percent cover of live oysters on the reef and documenting other reef associated fauna. This work is very labor intensive and involves visiting many reefs throughout the Reserve and laying down quadrats from which we take our measurements,” says Marcum. “We also monitor availability of oyster spat (baby oysters) in the water by deploying strings of shells monthly to collect the spat.” The shells are then brought back to the lab and observed under a dissecting microscope to count the number of spat that have settled on the shells.

GTM NERR has not just one, but three separate phytoplankton monitoring programs, and all of them are 100 percent led by volunteers. GTM NERR also participates in the Florida Fish and Wildlife Conservation Commission’s (FWC) Red Tide monitoring program, where volunteers go out monthly and collect water samples and measure water quality parameters on beaches within the Reserve.  Samples are then sent to an FWC lab to check for the presence of any harmful phytoplankton species.

GTM NERR citizen scientist volunteers also participate in the National Oceanic and Atmospheric Association’s (NOAA) Phytoplankton Monitoring Network (PMN). Volunteers take water samples and water quality measurements in the rivers behind the GTM office twice monthly. They bring the samples back to the lab to observe under microscopes the species present. If harmful species are found, samples are submitted to NOAA PMN for confirmation and documentation.

Finally, GTM researchers collect monthly water samples at Reserve water quality monitoring stations throughout the GTM NERR. Specially trained volunteers process the samples under a high-powered microscope to identify and count phytoplankton species present.

As a complement to the GTM SWMP vegetation monitoring, GTM also conducts annual mangrove surveys at two locations in the Reserve. Monitoring tracks landward changes in cover of mangroves as well as individual tree measurements for growth information.


Former GTM Biologist Jason Lynn measuring marsh elevation using a rod-Surface Elevation Table. (Credit: GTM Research Reserve)

Some monitoring is continuous, some is not. Water quality monitoring stations and the weather station are continuously monitoring stations that record data every 15 minutes. Water samples gathered to collect nutrient data, however, are taken monthly. Vegetation monitoring is conducted twice a year- in the spring and fall. Plankton monitoring varies, some samples are monthly while others are twice monthly. Oyster monitoring is conducted twice annually in the winter and in the summer.

Mangrove monitoring occurs annually in the fall.

GTM NERR is a great place to volunteer, with many volunteers coming from local high schools and colleges. GTM also provides assistance to students, both undergraduate and graduate from around the country, to conduct independent research projects within the GTM Research Reserve. GTM also has several programs that are run by citizen scientist volunteers including butterfly monitoring, nesting shorebird monitoring, plankton monitoring and sea turtle monitoring. “These programs are 100 percent volunteer-run programs,” says Marcum.

In her four years working at the Reserve, Marcum has seen some changes. “We have been able to use our data to show short-term impacts from recent storm events on water quality and vegetation. Continued monitoring will help us to better understand the resiliency of our estuarine systems,” she says. In addition, vegetation monitoring programs have documented an increase in cover and size of mangroves within the GTM Research Reserve. Because it is a monitoring program, the data does not provide causal information, however, other visiting researchers are further studying these changes to better understand driving factors.

“Many of our long-term monitoring programs are still in their early years, so we don’t have enough data to detect changes. We are currently working on a 10-year report for our water quality monitoring which will provide a summary of the data collected and trends. We hope to make it available later this year,” says Marcum.

Research at GTM NERR has held some surprises for Marcum. “It has been exciting to see how resilient our estuarine systems are here in the GTM Research Reserve. We’ve had several tropical systems come through our area in the last couple of years and our marshes and waters have stood up to them well,” she says.

The GTM Research Reserve is still a place where visitors can enjoy undisturbed natural areas. “It’s amazing to think that some of our viewsheds are what early settlers saw when they first came to northeast Florida. Places like this are becoming increasingly harder to find,” says Marcum. “I enjoy it here. I get to work in a beautiful place with other amazing people that are just as passionate about our research,” she enthuses.

In summary, Marcum encourages readers to reach out to their local Reserve, if they have one, and get involved. If anyone wants to explore the GTM data, it is available at www.nerrsdata.org and www.swmprats.net.

Top image: GTM SWMP Manager Shannon Dunnigan (top) and CTP Coordinator Kaitlyn Dietz working on the weather station. (Credit: GTM Research Reserve)

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